G Body Drag Car Alignment Settings

[Alky V6]

I need help from the alignment experts.

What are good settings (camber, caster and toe-in) for a G body that is strictly a drag car capable of mid 8s?

And please, please explain why any specs different than the OEM specs would be better for drag racing.

Is it recommended to have the driver in the car for the settings? OEM says car empty. Full fuel tank of course.

Is there an amount of artificial front end lift the car should be put at to simulate a raised front end during acceleration? One inch? Two inches?

For reference only. The 84 factory manual states:

Caster service checking +3.0 +/- 1.0 degrees. Service setting +3.0 +/- .5 degrees.

Camber service checking +.5 +/- .8 degrees. Service setting +.5 +/- .5 degrees.

Toe-in service checking .15 +/- .1 degrees. Servide setting +.15 +/- .05 degrees
(degrees per wheel)

Cross Caster service checking, no more than 1 degree side to side variation. Service setting, no more than .5 degree side to side variation.

Cross Camber service checking and service setting, same as above.

 

[charlief1]

I need help from the alignment experts.

What are good settings (camber, caster and toe-in) for a G body that is strictly a drag car capable of mid 8s?

And please, please explain why any specs different than the OEM specs would be better for drag racing.

Is it recommended to have the driver in the car for the settings? OEM says car empty. Full fuel tank of course.

Is there an amount of artificial front end lift the car should be put at to simulate a raised front end during acceleration? One inch? Two inches?

For reference only. The 84 factory manual states:

Caster service checking +3.0 +/- 1.0 degrees. Service setting +3.0 +/- .5 degrees.

Camber service checking +.5 +/- .8 degrees. Service setting +.5 +/- .5 degrees.

Toe-in service checking .15 +/- .1 degrees. Servide setting +.15 +/- .05 degrees
(degrees per wheel)

Cross Caster service checking, no more than 1 degree side to side variation. Service setting, no more than .5 degree side to side variation.

Cross Camber service checking and service setting, same as above.

Donnie, you should've PMd me. Granted I'm more of a road course guy but the same still applies. You want your camber about .1 to .2 negitive with you in the car and everything set up as you would run the car down the track. (Air bags ect loaded) The negitive setting will allow for better handling as the suspension loads and unloads. Remember, the camber curve in the metric G body cars is an issue as well as bump steer. When you get in the car it will change the settings to some degree but it depends on 1) position of the driver and 2) total weight of you and equiptment.
Caster needs to be over 4 degrees and is prefered at 4.5 degrees positive. The higher caster will wear tires on the edges when turning but it will keep the car going straighter. As an example, look at the caster wheels on your creeper. Granted it's not exactly the same but it is caster. The higher the caster the more the wheel will want to go straight. Make sure both sides have almost the same caster setting because the track should be fairly flat as oposed to roads that have a slight crown to allow rain run off.
If you have a set of toe plates set it for 1/16" to 3/32" in. Toe in is best because the drag on the tires will want to force the steering parts to pull outward unless you've changed to something like heim or rose joints which don't flex as much.
As far as the factory settings they are developed to allow for wear and provide the best overall ride and wear of the suspension for a street application and are not for performance purposes.
To get a better idea of what happens whe the front of the car lifts and drops, put a jack under the front center and lift it while watching how the tires move. They will go more negative camber wise as you lift it. If you have a way to lower the car you will notice the camber goes more positive.

 

[charlief1]

Here's some pics of some of the stuff we get up to around here. This should give you a better idea.:biggrin: And believe it or not it's considered a stock class car.

 

[Alky V6]

Donnie, you should've PMd me. Granted I'm more of a road course guy but the same still applies. You want your camber about .1 to .2 negitive with you in the car and everything set up as you would run the car down the track. (Air bags ect loaded) The negitive setting will allow for better handling as the suspension loads and unloads. Remember, the camber curve in the metric G body cars is an issue as well as bump steer. When you get in the car it will change the settings to some degree but it depends on 1) position of the driver and 2) total weight of you and equiptment.
Caster needs to be over 4 degrees and is prefered at 4.5 degrees positive. The higher caster will wear tires on the edges when turning but it will keep the car going straighter. As an example, look at the caster wheels on your creeper. Granted it's not exactly the same but it is caster. The higher the caster the more the wheel will want to go straight. Make sure both sides have almost the same caster setting because the track should be fairly flat as oposed to roads that have a slight crown to allow rain run off.
If you have a set of toe plates set it for 1/16" to 3/32" in. Toe in is best because the drag on the tires will want to force the steering parts to pull outward unless you've changed to something like heim or rose joints which don't flex as much.
As far as the factory settings they are developed to allow for wear and provide the best overall ride and wear of the suspension for a street application and are not for performance purposes.
To get a better idea of what happens whe the front of the car lifts and drops, put a jack under the front center and lift it while watching how the tires move. They will go more negative camber wise as you lift it. If you have a way to lower the car you will notice the camber goes more positive.

I was hoping you'd see this thread. You probably homed right in on it.

What about the artificial lift of the front end? Is it recommended? Is there a standard value to raise the front end?

 

[notacarlo]

Is the camber numbers of .1 and .2 negative used to off-set the weight of the driver? I thought a drag car, especially a brick like these needed to be at absolute zero....which might explain the short number on negative camber.

 

[charlief1]

I was hoping you'd see this thread. You probably homed right in on it.

What about the artificial lift of the front end? Is it recommended? Is there a standard value to raise the front end?

As far as a standard that depends on how high your car comes up on launch Donnie. With the .1-.2 negative camber and your car under load going down the track it will turn into slighty more negative which is ok but not ideal. If you have a way to measure how far up the front comes up under both launch and at the 1/8 then I can give you a better idea. It really depends on how the car rides after all.

Is the camber numbers of .1 and .2 negative used to off-set the weight of the driver? I thought a drag car, especially a brick like these needed to be at absolute zero....which might explain the short number on negative camber.

LOL Dan you are a virgin aren't you.:biggrin: Anytime weight is added to a chasis it will change the overall specs of camber and caster. That's why I told Donnie to make sure he's in the car with all the equiptment. I've had customers so large we didn't have a choice in the matter. (Not that Donnie is large btw) They had to be in the car so it could be set and go straight. When an unequal legnth A arm front end is lifted it will cause negative camber and if it goes down it will cause positive camber. With this in mind, once you get into the car the drivers side goes down and the pass side goes up.
Once the car settles down it usually stays about .1-.2 negative which is perfect for running. On a road car you set the camber closer to .5-1.0 negative so it will go around the corners with the tires laying as flat as possible.

 

[Alky V6]

Charlie. Maybe you can confirm something for me. I understand that positive camber is not the best for cornering. Negative being better, particularly on the outer wheel with the most load on it. I have heard that the OEMs actually build positive camber into the production cars for when in corners to keep people from being road warriors with their cars. Is that true?

 

[charlief1]

The factory sets most cars up so the nose dive effect comes into play to keep the customer safe. You are correct on that. To give you a better idea, my second car was a 76 Skyhawk that I had set up for SCCA competition. They come with negative caster from the factory so even if you have everything set right it will loose traction on a high speed corner around 85 if the corner is fairly tight. I've slid off several tracks.
Remember that when the chasis is loaded one tire will go negative and one will go positive if the car is set right. (In a corner that is) You want the one being loaded to go negative so it will have better traction. Even if the other wheel leaves the ground the loaded tire has the grip so it will keep you in place better.
As much as I hate to bring it up, look at Odels video crash and watch how the front end reacts when he got out of the grove. If his right front tire had a little more traction he might have been able to pull her into a straighter line and the wreck might not have been as bad. Just and observance So don't shoot me please.
The more you increase the negative camber the more your tire rides on the inner edge so there is a wear factor for street use. Since this is a track only car you want the negative camber to cut down on tire drag slightly. You still have a decent amount of control so you can make it go straight but if, for some reason, you go sideways enough, the tire on the loaded side will have more grip so you might be able to pull out.

 

[Alky V6]

I understand. Very nice explanation. Thanks.

 

[charlief1]

I'm gonna save everyone and myself some aggrivation in the long run. As far as a street alignment use 3.25 degrees positive caster on the pass side and .35 to .5 lower on the drivers side. If you can achieve a .4 to .45 diff with the drivers side lower it will work best and give a slight drift to the shoulder in case something happens to the driver. This way you don't end up drifting into on coming traffic.
Also, Please post the question here so everyone can benifit from the info please.

 

[charlief1]

Not a problem Donnie. You've helped my understanding on other things as well so we've helped each other for sure. Any other question?

 

[Alky V6]

Charlie. Can you describe any cheap methods of doing a home alignment? I have a digital level and can cut a piece of metal to span the wheel diameter.
Describe any homemade alignment tools?
Method for getting the caster angle?

I know you've got to have some cheap tricks.

 

[charlief1]

Charlie. Can you describe any cheap methods of doing a home alignment? I have a digital level and can cut a piece of metal to span the wheel diameter.
Describe any homemade alignment tools?
Method for getting the caster angle?

I know you've got to have some cheap tricks.

Cheap is relative Donnie. Toe plates are cheap fom a dirt track suplier but you need turn tables to set caster and the car must be on a completely level surface. Then you need a camber guage and you have to know how to read it. Not a very easy thing if you don't know how to use it.
I'll give you an idea. Once the car is on the pads and level you must turn each wheel 30 degrees left and right, take a reading of both wheels. This will give you two # and the formula is kinda long. If you want I'll see if I can find my notes from when I was in school. Been a long time but I think I can find them. There is also SAI shich can screw you up. Since you've got a slightly damaged chasis and the car is only for the track now, it won't be a problem.

 

[Alky V6]

Do you have a link to a site that has good equipment reasonably priced?

 

[charlief1]

Do you have a link to a site that has good equipment reasonably priced?

Longacre Steering Accessories
IMCA Stock Car A-Arms
JOES Racing Products designs items to meet the demands of the racing market. Check out our full line of high quality items and browse our website to find great products that track tested and simple to use. - JOES Racing Products
Intercomp Bubble Caster/Camber Gauge - JEGS
Intercomp Digital Caster/Camber Gauge - JEGS
* Camber Gauge and Castor Tools *
Longacre Racing Online -- Online Catalog

An atricle on how to do it
How to: Measuring Caster and Camber - How To - Circle Track Magazine

This should help some Donnie. My boss paid about 10k for the one we have right now and it's used. The equiptment isn't cheap but it is handy after all.:biggrin: If you do some searches for "camber gauge" you'll find more out there. I just did a quick one to help you.

 

[Alky V6]

Holy cow, Charlie. Thanks. I'll be busy for the next day or so.

 

[charlief1]

Holy cow, Charlie. Thanks. I'll be busy for the next day or so.

Better copy them fast Donnie. You know how links can disappear around here.lol
I forgot to add that the one with the asterics is one of the best but it is kinda pricey.

 

[Alky V6]

Better copy them fast Donnie. You know how links can disappear around here.lol
I forgot to add that the one with the asterics is one of the best but it is kinda pricey.

Done.
I may do the bubble deal and the toe-in plates. I don't think I really need more than 1/4 degree accuracy.

 

[charlief1]

Done.
I may do the bubble deal and the toe-in plates. I don't think I really need more than 1/4 degree accuracy.

The only way you'll know for sure Donnie is to drive it down the track and see how she feels. If you have the oportunity to drive slowly and get up some speed to feel for any pull or drift you would be better off. One other option is to take the car to an alignment shop, talk to the techs there to see if they really know what they're doing, and have it set by them for the first time. Then do the camber gauge and mark down what you find so you can repeat the settings. This goes for both the toe plates and the camber gauge. When you get everything done post it one here with some pics for the others Donnie.

 

[notacarlo]

LOL Dan you are a virgin aren't you.:biggrin: Anytime weight is added to a chasis it will change the overall specs of camber and caster. That's why I told Donnie to make sure he's in the car with all the equiptment. I've had customers so large we didn't have a choice in the matter. (Not that Donnie is large btw) They had to be in the car so it could be set and go straight. When an unequal legnth A arm front end is lifted it will cause negative camber and if it goes down it will cause positive camber. With this in mind, once you get into the car the drivers side goes down and the pass side goes up.
Once the car settles down it usually stays about .1-.2 negative which is perfect for running. On a road car you set the camber closer to .5-1.0 negative so it will go around the corners with the tires laying as flat as possible.

Yeah...that's what I meant. You set it over to compensate for my fat tub in the pilots seat. It may be at .1 or.2, but once the butt is in the basket it would settle to 0.
I've done alignments with plumb bobs, duct tape and string. Of course I am being told what to set the car to.